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Flashcards in 2015.04.15 Deck (63)
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1
Q

Virion/Virion protein binding specificities

A

CD4 (and coreceptor CCR5 or CXCR4) and HIV gp120

CD21 and EBV gp350

Erythrocyte P antigen and Parvovirus B19

2
Q

Congenital Torticollis

A

Develops 2-4 weeks of age. Head is tilted to affected side.

Caused by birth trauma or malposition of the head in utero which results in sternocleidomastoid muscle injury and fibrosis.

May have hip dysplasia, metatarsus adductus (adduction of forefoot) and talipes equinovarus (clubfoot).

3
Q

Defective fetal collagen synthesis

A

causes osteogenesis imperfecta (brittle bone disease)

Patients with lethal variety die in utero or in infancy due to severe fractures, pulmonary failure, or intracerebral hemorrhage

4
Q

Fetal Alcohol Syndrome

A

poor growth, functional developmental deficits, characteristic facial abnormalities: smooth philtrum, thin vermillion border, and small palpebral fissures.

5
Q

Inferior MIs is due to which artery?

A

Blockage of the right coronary artery (usually responsible for SA and AV nodes) leading to bradycardia.

Atropine (antimuscarine) is given to block vagal influence on SA and AV node and increases heart rate.

6
Q

Mental retardation, dysmorphic facial features (large jaw, protruding ears), macroorchidism

A

Fragile X Syndrome

7
Q

Short stature, broad (shield) chest, webbed neck, low hair line

streaked ovaries leading to primary amenorrhea

A

Turner’s syndrome (45 XO)

8
Q

Tall stature, gynecomastia, small, firm testes

Decreased testosterone secretion by fibrotic testes causes oligospermia and infertility

A

Klinefelter Syndrome (47 XXY)

9
Q

Arachnodactlylyl, scoliosis, aortic root dilation, lens dislocation (ectopia lentis), mitral valve prolapse

A

Marfan Syndrome

10
Q

Cleft palate associated with which disorder?

A

Trisomy 13 (Patau syndrome)

11
Q

Polydactylyl is associated with?

A

Trisomy 13 (Patau syndrome)

12
Q

Rocker-botton feet is associated with?

A

Trisomy 13 + 18

13
Q

Minimal Change Disease

A

Selective proteinuria: LMW proteins such as albumin and transferrin are excreted because loss of negatively charged molecules on glomerular basement membrane (no charge to repel albumin) allows small proteins through filtration barrier.

14
Q

Tubular proteinuria

A

Proximal tubular function is disrupted (like in tubulointerstitial nephritis)

Proteins that are normally filtered by glomerulus and completely reabsorbed by proximal tubule are lost - LMW proteins, b2-microglobulin, Ig light chains, aa, retinol-binding protein.

15
Q

Dorsal pancreatic bud

A

forms the pancreatic tail, body, most of the head, and the small accessory pancreatic duct.

16
Q

Ventral pancreatic bud

A

Uncinate process, inferior/posterior portion of the head, and major pancreatic duct (of Wirsung).

17
Q

Pancreatic divisum

A

failure of dorsal and ventral pancreatic buds to fuse.

Pancreatic ductal systems remain separate, with accessory duct (of Santorini) draining the majority of the pancreas.

18
Q

Obesity, hirsutism, oligomenorrhea

A

Polycystic ovarian syndrome (PCOS)

Due to abnormality of the hypothalamic-pituitary-ovarian system.

Androgen (testosterone and androstenedione) and LH levels are elevated, whereas FSH levels are normal.

High levels of unopposed estorgen on endometrium increases risk of endometrial hyperplasia and endometrial adenocarcinoma.

Increased insulin resistance puts at risk for DM2

19
Q

Vaginal adenosis

A

replacement of vaginal squamous epithelium with glandular columnar epithelium.

due to exposure of diethylstilbestrol (DES) when pregnant

precursor for clear cell adenocarcinoma of the vagina

20
Q

Central chemoreceptors

A

located in medulla

stimulated by decreases in pH of CSF

Increased PaCO2 is the major stimulator, leading to increase in respiration.

21
Q

Peripheral chemoreceptors

A

found on carotid and aortic bodies

primary sites for sensing arterial PaO2 and are stimulated by hypoxemia

can also be stimulated by PaCO2 levels and blood H+ concentration, but central chemoreceptors are more responsive to hypercapnia

22
Q

Small nuclear ribonucleoprotein particles (snRNPs)

A

important components of the spliceosome, a molecule which functions to remove introns from pre-mRNA during processing within the nucleus

23
Q

Nucleosomes

A

Histone protein cores around which dsDNA is wrapped.

Nucleosomes are important for compact packaging of dsDNA into chromosomes.

24
Q

Low-grade fever, headache, malaise, and upper respiratory syndromes followed up sudden appearance of erythematous malar rash with circumoral pallor 2-5 days later

A

Erythema Infectiosum (“fifth disease”) due to Parvovirus B19.

Virus is highly tropic for erythroid precursor cells and replicates predominantly in the bone marrow.

25
Q

MacConkey agar

A

gram - organisms that ferment lactose, cause drop in pH, resulting in colonies with a pink-red appearance

E. coli, Klebsiella, Enterobacter

26
Q

Major virulence factor among E. coli strains that cause neonatal meningitis

A

K1 capsular antigen (immunogenic)

anti-capsular antibodies are protective

27
Q

Anesthesia near the tip of ischial spine

A

Pudendal nerve block (S2-S4 nerve roots) which provides sensory innervation to the perineum and genitals as well as motor innervation to sphincter urethrae and external anal sphincter

28
Q

Warfarin elimination

A

Cytochrome P450

Inhibit P450 2C9: increase warfarin’s anticoagulant activity - Cimetidine, amiodarone, and TMP-SMX

Increase P450 activity: decrease warfarin’s anticoagulant activity - Rifampicin, phenobarbital, phenytoin

29
Q

Rituximab

A

Monoclonal antibody directed against CD20 antigen.

Used in lymphoma immunotherapy

30
Q

Infliximab

A

Chimeric (human/murine) IgG1 monoclonal antibody to TNF-alpha.

Rheumatoid arthritis, ankylosing spondylitis, fistulizing Crohn’s disease

31
Q

Imatinib mesylate

A

Potent inhibitor of the BCR/ABL protein tyrosine kinase

inhibits cellular proliferation of BCR/ABL-expressing cells.

Treatment of CML

32
Q

Abciximab

A

Chimeric mouse-human monoclonal antibody against the platelet GP IIb/IIIa receptor

blocks final step in platelet aggregation

administered during angioplasty in patients with acute coronary syndrome

33
Q

Trazodone

A

Sedating effects and can be used with Fluoxetine to treat patients with depression and accompanying insomnia.

No anticholinergic or cardiac effects

cause priapism

34
Q

Positive Tinel and/or Phalen test

A

Tinel sign - tapping over flexor surface of the wrist reproduces symptoms

Phalen sign - flexion of wrist reproduces symptons

Carpal Tunnel Syndrome.

35
Q

Lipopolysaccharide (LPS)

A

O antigen

Core Polysaccharide

Lipid A - responsible for toxic properties of LPS and lead to gram- sepsis and endotoxic septic shock (activates macrophages and granulocytes - IL-1, PG, TNF-a, interferon)

36
Q

Fimbriae, pili, are a virulence factor in which organisms?

A

Neisseria meningitidis

Urothpathogenic and diarrheogenic E. coli

Bordetella pertussis

Vibrio cholerae

37
Q

Flagellar (H) antigen

A

heat-labile protein which is one component of the serologic classifciation of enterobacteriaceae

38
Q

Superior mesentery artery syndrome

A

transverse portion of duoden is entrapped between the SMA and aorta (decreased aortomesenteric angle secondary to dimished mesenteric fat, pronounced lordosis, or surgical correction of scoliosis), causing symptoms of partial intestinal obstruction.

39
Q

Chemoreceptor trigger zone (CTZ) location

A

dorsal surface of medulla at the caudal end of the fourth ventricle in a region known as the area postrema (receives blood from fenestrated vessels - absent blood-brain barrier - which allows it to sample chemicals circulating in the blood)

40
Q

Treating hypertension or CHF in a woman who is at risk for osteoporosis

A

Hydrochlorothiazide (increases absorption of calcium from the DCT, also helps lower renal stones)

Furosemide (loop diuretic) will increase urinary calcium loss, making it a poor choice.

41
Q

Phase 4 of Cardiac pacemaker cells

A

slow, inward sodium current during this diastolic depolarization phase

augmented by transient inward calcium currents

Verapamil is calcium channel blocker and class IV antiarrhythmic drug - slows depolarization in phase 0 and latter phase 4 (decreases SA node firing and slows AV node conduction)

42
Q

Medications with negative chronotropic effects (decreased heart rate)

A

Beta-blockers

Non-dihydropyridine calcium channel blockers (verapamil, dilitiazem)

Cardiac glycosides (digoxin)

Amiodarone and sotalol

Cholinergic agonists (pilocarpine, rivastigamine)

43
Q

Combined use of non-dihydropyridine calcium channel blockers (verapamil, diltiazem) and beta-blockers

A

negative chronotropic effects yielding severe bradycardia and hypotension

44
Q

Vasodilation and reflex tachycardia

A

ACE inhibitors

Nitrates

Peripheral a1-selective adrenergic blockers (prazosin)

45
Q

Nifedipine

A

Dihydropyridine calcium channel blocker with minimal effects on SA node and cardiac conduction.

Predominantly used as vasodilator and can cause a reflex increase in heart rate

46
Q

Proton pump inhibitors and osteoporosis

A

long-term acid suppression with proton pump inhibitors decrease calcium absorption (calcium needs acidic environment for proper absorption) and thus leads to increased risk of osteoporotic hip fractures.

47
Q

VIPomas

A

non-beta cell pancreatic islet cell tumors that hypersecrete vasoactive intestinal polypeptide (VIP)

causes excess loss of water, sodium, and potassium in stool and inhibits gastric acid secretion

Watery diarrhea, hypokalemia, achlorhydria (WDHA)

48
Q

Inactivated viral components vaccine

A

Influenza vaccines are inactivated when adminstered by injection.

Generate a humoral immune response (instead of cell-mediated which is generated by live-attenuated viral vaccines)

Neutralizing antibodies are induced against the hemagglutinin antigen (antibodies will inhibit binding of hemagglutinin to sialyated receptors on the host cell membrane, preventing live virus from entering cells via endocytosis)

49
Q

Oseltamivir

A

sialic acid that competitively inhibits influenza neuramidase (cleaves terminal sialiac acid residues on glyconjugate receptors, allowing for release of attached influenza virions from infected cells), preventing release of viral progeny

50
Q

Aldolase B

A

participates in fructose metabolism, deficiency in this enzyme results in fructose intolerance

hypoglycemia following fructose ingestion due to phosphate trapping in fructose-6-phosphate

fructose and sucrose should be removed from diet

51
Q

Watershed infarction

A

systemic hypotension (due to abdominal aortic aneurysm for example) can cause ischemia and necrosis of intestinal wall in areas with slow perfusion.

Splenic flexure and distal sigmoid colon most susceptible

Splenic flexure: “border” area between the distribution of SMA and IMA arteries.

Distal sigmoid colon: between areas supplied by IMA and hypogastric arteries

52
Q

Lac operon regulation

A
  1. Negatively by binding of the repressor protein (made from lac I) to the operator locus
  2. Positively by cAMP-CAP (catabolite activator protein) binding upstream from the promotor region (cAMP levels need to be high, glucose decreases activity of adenylyl cyclase, reducing intracellular cAMP; thus lac operon is repressed in high-glucose conditions)

Lac operon encodes for lac Z (b-galactosidase) and lac Y (permease - allows lactose to enter bacterium)

53
Q

Hemosiderin

A

aggregation of ferritin micelles (iron binds to apoferritin when iron is deposited in cells)

54
Q

Paraneoplastic cerebellar degeneration

A

progressively worsening dizziness, limb and truncal ataxia, dysarthria, and visual disturbances

due to immune response against tumor cells that cross-react with Purkinje neuron antigens, leading to acute-onset rapid degeneration of the cerebellum

Anti-Yo, anti-P/Q and anti-Hu are most common.

55
Q

Subacute thyroiditis (de Quervain’s thyroiditis or granulomatous tyroiditis)

A

thyrotoxicosis (due to release of stored thyroid secondary to thryoid inflammation, tenderness over the thyroid gland, increased ESR, and markedly reduced radioactive iodine uptake (no excess production of thyroid hormone, which is why iodine uptake is decreased).

Mixed, cellular inflammation with occasional multinucleate giant cells surround the fragmented colloid

thryotoxic phase is followed by hypothyroid phase for a few months

56
Q

Hashimoto’s thyroiditis

A

diffuse mononuclear infiltration with formation of germinal centers (infiltrate contains lymphocytes and plasma cells)

thyroid enlargement (goiter) and/or hypothyroidism

differenatiate from other thyroid dysfunction: normal ESSR, nontender thyroid gland with rubbery texture, high titers of antithyroid peroxidase antibody, hypothyrodism

57
Q

Riedel thyroiditis

A

extensive fibrosis involving the thyroid gland.

fibrosis can extend into surrounding structure.

58
Q

True hydrocephalus

A

increase in CSF volume and pressure that occurs due to abnormal production, flow, or absorption of CSF

the pressure then causes ventricular enlargement

59
Q

Hydrocephalus ex vacuo

A

ventricular enlargement due to brain atrophy and is not accompanied by increase in CSF pressure

occurs in Alzheimer, Pick disease, advanced HIV infection etc secondary to atrophy of the brain

60
Q

Communicating hydrocephalus

A

CSF flows freely between the ventricules and subarachnoid space

caused by decreased CSF reabsorption secondary to subarachnoid villi inflammation (as in subarachnoid/intraventricular hemorrage or meningitis) or certain congenital malformations

entire ventricular system is dilated

61
Q

Pseudotumor cerebri (idiopathic intracranial hypertension)

A

elevated intercranial pressure with normal CSF content and normal neuro-imaging

in young, obese women and manifests as headache and papilledema

optic nerve atrophy and blindness are possible sequealae

62
Q

Lissencephaly

A

agyria

congenital absence of gyri

severe mental retardation

brain surface has smooth appearance

63
Q

Transtentorial (Uncal) herniation

A

due to intracranial mass or cerebral edema

herniation of parahippocampal uncus through the tentorial incisure leads to compression of ipsilateral CN III and posterior cerebral artery

fixed, dilated pupil on same side as lesion is the first sign of uncal herniation